6 Answers

You can’t save him on your own. and I don’t think we can really do anything to help you do that. If he is considering suicide, you need to get him professional help. Refer him to a therapist, the hotline (probably best) 1–800-273–8255 or, if he’s under 18, his parents.
If you think he is in serious danger, call the cops.
I don’t mean to be negative, but if he is telling you he is considering suicide, he is seeking help. People don’t talk about killing themselves, joke about it, etc if they aren’t looking for help.(usually) If he already had his mind made up, he would do it without mentioning it.You need to get him help if you are worried or if he is considering it

Even if you are worried about him hating you/whatever. It’s better to be safe than sorry

@SergeantQueen is correct. He is seeking help by telling you. Get him in touch with people much more qualified than us to help him. Most cities have a suicide hotline. Find out what it is.
This is a serious matter and should be treated as such.
Good luck